Alternator over voltage

Discussion in 'American RV's' started by olley, Mar 30, 2009.

  1. olley

    olley Funster

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    Hi after discovering my batteries are apparently U/S I checked the alternator voltage, its constant at around 14.7, odd thing is I rarely have had to top up the engine battery, the house are sealed so no idea what there like.

    So it looks like the regulator is u/s. :cry:

    Olley
     
  2. scotjimland

    scotjimland Funster Life Member

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    Hi Olley

    is it the starter battery that's u/s ? If so, could that not be the cause of the constant 14.7v ? .. duff battery, alternator keeps trying to top it up ?

    jat

    Jim
     
  3. olley

    olley Funster

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    Hi Jim wish that was all, :cry: battery monitor registered 36ah before the inverter low voltage kicked in at Newark. Thats on a 540ah battery bank, so it looks like their all stuffed.

    Just phoned West midland, £285 for a new alternator plus about £50 to fit, I could do it myself, but it looks a bit of a barsteward, so I thought for £50 let someone else struggle. :BigGrin:

    Then going to need new batteries :cry::cry: but not this year.

    Olley
     
  4. Douglas

    Douglas Read Only Funster

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    Olley,

    Is your engine computer controlled? if so its possible that the alternator is not controlled by a voltage sensor in the alternator ie 13.6v max but by the computer that will take it passed the gossing voltage, around 14.2

    Doug...
     
  5. olley

    olley Funster

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    Hi Doug, never heard of an ECU doing that, is it something that you get on europeons? I will post on IR2.com and ask the yankee gurus on there, but I don't think it does.

    Before ordering the alternator I asked Dave at West Midland if they could supply the regulator only, but he said they are basically "throw away components" :Sad: its the lot or nothing.

    Seems odd in this day and age when we are supposed to be recycling that this is allowed.

    Olley
     
  6. Douglas

    Douglas Read Only Funster

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    Yes the on board computer on some engines also control the battery charging, before that there were and still are stand alone control units to control the alternator so that the batteries are charged 100% instead of 80% which is the case with a alternator built in control.

    But if there is a throw away regulator on your van it sound like you don't have the computer control system and in which case every thing I have said is of no use to you, I only wanted to stop you going down the wrong path.
     
  7. damondunc

    damondunc Funster

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    over charging

    The alternator on 8.1 2004 engines is computer controlled, the workhorse manual you gave me a while ago has the details on it. Look at the 2004 chassis supplement page 743 onwards it gives a load of stuff about it, unfortunately you need a tech 2 scanner to get to the fault codes, west midland have one. It may be worth looking at the multiplug on the side of the alternator, i've had 2 with corroded connectors that gave charging problems.
    regards dunc.

    PS only remove this plug with the ignition switched off!
     
  8. olley

    olley Funster

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    Hi Duncan, thanks for the info, had a good read and unless I am mistaken it can be turned off/on only by the PCM, the PCM doesn't control the voltage, that's done by the alternators regulator, the PCM also monitors the system voltage, above 19 or below 11 it sets a fault code and the engine goes into limp mode.

    According to the manual anywhere between 11-15.5v off load is ok.

    I was getting quite excited there for a while :cry: thought it might be something West Midland could change with a tech2.

    I have been able to identify the alternator from the manual though, its an ACDELCO AD244 available in the states for $200 :cry:

    Still looks a barsteward to fit without a pit through.

    Olley
     
    Last edited: Mar 30, 2009
  9. ruffingitsmoothly

    ruffingitsmoothly Read Only Funster

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    Hi Olley

    Sorry to hijack your thread but I have heard that running the engine whilst on hookup can damage the alternator:Sad: anyone know if this is true or not[​IMG][​IMG]

    Regards Pat
     
  10. hereford bull

    hereford bull Read Only Funster

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    Ive done this before i knew better and the alternator warning light comes on on the dash
     
  11. olley

    olley Funster

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    Hi Pat, only thing I can think of is that your charger and alternator would be working together, why that would cause a problem I don't know? maybe somebody could shed some light?

    Olley
     
  12. olley

    olley Funster

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    Hi been talking to Driver on IRV2.com and he reckons 14.7v or thereabouts is ok. His RV apprently reads around 14.6v and he's never had any battery troubles.

    I have had it on EHU since Sunday night, so tomorrow I will unplug it and do a load test and see how long they last.

    Olley
     
  13. olley

    olley Funster

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    Just did the load test the battery monitor recorded 43ah at which point the voltage had dropped to 10.9v, that's on a load of around 17amps on a fully charged 540ah battery bank.

    They look absolutely fine and after an hour off load they have returned to 12.5v but put the load back on and they go down very quickly.

    So its new battery time, local manufacturer recommended by scotjim is selling 210ah for £137 inc tax, which sounds pretty good.

    Olley
     
  14. scotjimland

    scotjimland Funster Life Member

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    Glad to be of assistance Olley .. if any one else is looking for quality batteries, direct from the factory ( no middle man) .. give these folks a call .

    Lincon Batteries - Manufacturers and suppliers of classic car batteries, commercial vehicle batteries, marine batteries, motorcycles batteries and more

    In Southend on Sea .. but can deliver .. :thumb:
     
  15. johnsandywhite

    johnsandywhite Read Only Funster

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    :Cool: It only cost us £185 for our Coachmen one (after I'd had the old one re-built - waste of money). A doddle to fit . If I were there? I'd fit it for nowt. :thumb:


    BTW. My cheapo AGM's are still going great guns .
     
    Last edited: Apr 1, 2009
  16. olley

    olley Funster

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    Hi getting more info about the alternator, apparently its regulator is set at 14.8 by Delco :Eeek: they say its the wrong alternator for the job.

    They do produce one with a regulator set at 14.4 but its almost impossible to obtain. Getting quite a few more people complaining of the same problem, so looks like I will have to come up with a fix or replace the batteries every few years. :cry:

    The simplest solution is to isolate the house batteries from the alternator with a heavy duty switch and accept that the engine battery will need replacing every few years.

    A more complicated idea is to do the above, and use some heavy duty change over relays to swop the inverter from the house, to the engine batteries while the engine is running; and let it power the sterling 4 stage battery charger.

    Olley
     
  17. olley

    olley Funster

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    Hi more info, the alternator was designed to be used with a solid state battery isolator, which would give the necessary voltage drop.

    So one of the yank posters has suggested using a split charge diode, just had a look on Sterlings site and they say .6 of a volt drop across their 160amp diode minimum, £100 but if it cures the problem, its got to be money well spent. What do you reckon?

    Olley
     
  18. scotjimland

    scotjimland Funster Life Member

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    Hi Ian

    Seems a lot of dosh to lose .6V .. :Eek!:

    could you not just open the house battery isolator when travelling.. ? just an idea..

    Jim
     
  19. olley

    olley Funster

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    Hi Jim that would still mean a knackered engine battery every few years. :Sad: I got the present one at the sametime as the house batteries, and I have to use the emergency start most times now to start the engine, which is one reason why the battery mode relay; keeps going up the spout. I have sent an email off to Sterling, just to see if they can see any problems, if they can't then that's what I will fit.

    At Newark we ran out of leccy at 21.00 on Friday night, you ought to have heard the moaning as the telly went off. :BigGrin: I was on my little lappy so wasn't bothered.

    I hate running the genny with other people about, but in the morning when I went walkabout with archie at around 08.00 2 or 3 had them going so I started ours. (safety in numbers) :BigGrin:

    Olley
     

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